1. Field of the Invention
This invention relates generally to coaxial connectors, more particularlly to a female connector having conductive shell and a protective member, and a method of making such a female connector.
2. Description of the Prior Art
Female coaxial connectors of such a type are disclosed in Japanese U.M. Patent Kokai No. 59-138184. These connectors have a cylindrical conductive shell for receiving a mating male connector to make an electrical connection. This cylindrical conductive shell has a plurality of open slits so that it may have sufficient elasticity to receive a mating male connector. However, the female coaxial connectors of this type have the following disadvantages:
(1) Since the slits of the conductive shell are provided in the axial direction, the mating male connector must be wrenched in the radial direction into the female conductive shell for connection or disconnection. This deforms the shell, resulting in a poor connection. When the wrenching force exceeds the allowed limits of its material, the shell undergoes plastic deformation or even breakdown.
(2) The conductive shell is contracted toward its open end with the aid of slits so that it may fit tightly over the male connector. However, this is a liner contact at the upper circumference of the female conductive shell, resulting in a very unstable contact.
(3) The cutting of slits on the circumference of the conductive shell requires high precision. Consequently, it needs a complex cutting process, making its mass production process impossible or very expensive if possible at all.
(4) After the cutting, the open end of the contacting portion must be contracted manually with a contracting tool to give elasticity to the connecting portion. This is unsuited to its mass production, thus raising its manufacturing cost. In addition, the product quality is very unstable; the force for connection or disconnection or the contact strength varies from connector to connector resulting from the manual contracting operation.
(5) The connecting portion of the external conductor has no locking means for the mating connector. Consequently, there is a danger of disconnection due to the pull or vibration or impact applied to the cable, resulting in the lower connector reliability.
(6) The lists provided on the connecting prortion of the external conductor cause a leak of electromagnetic waves, degrading the electrical characteristics of the connector.